Articulatable control vane



P 25, 2 M. e. BRISLAWN, JR 3,055,618

ARTICULATABLE CONTROL VANE Filed Jan. 6, 1959 2 Sheets-Sheet 1 INVENTOR. 59/51. m wv' Y z 4 Arrive/v52.

I 16 I 0 Z I 7J2mumlllllllllllllm p 1962 M. e. BRISLAWN, JR 3,055,618

ARTICULATABLE CONTROL VANE Filed Jan. 6, 1959 2 Sheets-Sheet 2 IN V EN TOR. Mae 6. .BE/SLfiW/V M wfw UnitedStates Patent flice 3,055,618 Patented Sept. 25, 1962 Filed Jan. 6, 1959, Ser. No. 785,180 14 Claims. (Cl. 244-87) The present invention relates to an articulatable control vane adapted to be varied between positions wherein the upper camber is fully positive, neutral and fully negative. The invention is directed to a vane capable of producing control forces of high magnitude under conditions of fluid flow or angle of attack which destroy or render ineffective the expected control forces derived from a rigid, single element vane.

The articulated control vane of the present invention is perfectly symmetrical in the neutral position and thus produces substantially no drag. When the vanes upper camber is varied into either the fully negative position or fully positive position, a smoothly curved vane is provided for deflection of the fluid stream to produce an oppositely directed maximum control force. This maximum control force is produced, for any curvature of the vane, because there is a smooth flow of fluid over the outer surfaces of the vane, permitting changes in direction of flow of fluid in excess of 40". When the flow of fluid becomes turbulent and rough (as when a single element, rigid vane is inclined to about l8-22 to the flow of fluid), the magnitude of the reacting control force or normal force on the vane diminishes and becomes unavailable. This turbulent fluid flow condition, aerodynamically is called a stalled condition, and any movement increasing the angle of the vane beyond the stall angle is accompanied by an increase in the drag of the vane with diminishing vertical reacting forces which are available for controlling purposes.

The present invention therefore provides an articulatable vane capable of deflecting a stream of fluid without turbulence to produce a normal reacting force for control purposes which is greater in magnitude than that produced by control vanes used heretofore. The present controllably articulatable vane, in general, includes a central section, a nose section and a flap section, each section being symmetrical about its median line. The nose and flap sections are pivotally connected, respectively, to the upstream and downstream portions of the central section about axes passing through the central section so that in the neutral position of the articulated vane the median lines of all of said sections are in alignment to provide a symmetrical vane having outer contours of virtually no drag.

Means are provided for imparting controlled rotation to the sections to vary the upper camber of the vane into all positions between and including fully positive and fully negative. In any position, the sections are interconnected so as to provide a smoothly curved vane which will not cause turbulent flow of the fluid.

The vane of the present invention also includes an additional feature for producing a normal force of greater magnitude. The downstream end of the central section may be symmetrically tapered in a downstream direction about its median line and terminate adjacent the upstream portion of the flap section. When the sections are rotated relative to each other to vary the upper camber of the vane, a slot is formed between the tapered downstream portion of the central section and the upstream portion of the flap section to allow fluid to pass from the high pressure side of the vane to the low pressure side of the vane. This improves the flow conditions of the fluid about the vane and decreases turbulence and drag as the fluid is deflected to produce a greater normal, control force on the vane.

An object of the present invention is the provision of an articulatable vane which is capable of having its upper camber varied between positions of fully positive, neutral and fully negative.

An object is to provide an articulatable vane construction capable of being effectively used as a control surface in fluid streams, the vane of this invention being capable of being positioned at angles greatly in excess of those at which a rigid vane produces turbulent flow, excessive drag and negligible control forces or normal forces; the construction herein disclosed produces effective control forces which are up to over higher than those capable of attainment with a single element, rigid vane.

Another object is to provide a vane having articulatable sections capable of being pivoted to form a substantially smoothly curved surface which will not produce a turbulent fluid flow when the upper camber of the vane is varied into positions between fully positive and fully negative.

A further object of the invention is to provide an articulatable control vane capable of having its upper camber varied and in doing so provides a slot for allowing fluid to flow from the high pressure side of the vane to the low pressure side of the vane to eliminate turbulence or burbling of the fluid.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

FIG. 1 shows a perspective view of an articulatable vane which is illustrative of the present invention;

FIG. 2 is a side elevation of the vane shown in-FIG. 1, in neutral position;

FIG. 3 is a longitudinal section of the vane with the upper camber thereof in a fully positive position;

FIG. 4 is a longitudinal section of another embodiment of the vane of the present invention, in a neutral position; and

FIG. 5 is a side elevation of a thrust propulsion unit having a plurality of articulatable vanes of the present invention pivotally mounted therein.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts through out the various views, there is shown in FIG. 1 an articulatable vane 10 having a central section 12, a nose section 11 and a flap section 13. This vane is adapted to be positioned in a fluid stream (as in FIG. 5 for example) and adapted to be varied between positions where the upper camber is fully positive (FIG. 3), neutral (FIG. 2) and fully negative (a reverse of the position shown in FIG. 3). 1

The nose section 11, having a suitably rounded entering or leading edge, is pivotally connected to the upstream portion 12a of the central section 12 about an axis passing through the median line 12' of the central section. A pair of levers 15 and 15 may be rigidly secured to the ends of the nose section 11 and pivotally connected to or journalled upon the ends of a transversely extending shaft 14 mounted on the upstream portion 12a of the central nose section. The downstream portion 11b of the nose section 11 may be concaved so as to receive and approach the convexed upstream portion 12a of the central section. By having the nose and central sections formed in such manner the outer contours of the central section are an eifective continuation of the nose section which prevents premature separation of the fluid and thus aids in attaining the maximum control force.

In a similar manner, the ends of the flap section 13 may be provided with a pair of levers 17 and 17' for pivotally connecting the flap section to the downstream portion 12b of the central section 12 about an axis passing through the median line 12 of the central section. A transversely extending shaft 14' may be mounted on the downstream portion 12b of the central section and its ends pivotally positioned within the levers 17 and 17 The levers are rigidly secured to the flap 13 in any convenient manner. It should be understood that each of the shafts 14 and 14' could be replaced with a pair of butt shafts to pivotally connect the flap and nose sections on the central section.

The downstream portion of the central section 12b may be symmetrically tapered in a downstream direction about its median line 12 to terminate in a spanwise edge 120 immediately adjacent the upstream portion 13a of the flap section 13 in the neutral position (FIG. 2). This taper is restricted to the area of the downstream portion 12b of the section 12 surrounding the shaft 14' and is an abrupt curvature of the outer contours to form concave surfaces terminating in the edge 120. The upstream portion 13a of the flap section may be rounded and may have a substantial thickness 0 as to cooperate with the spanwise edge 120 to form a slot therebetween (FIG. 3) for allowing fluid to pass from the high pressure side of the vane to the low pressure side of the vane to reduce turbulence or burbling in a manner to be further described hereinafter.

The central section 12 may be pivotally mounted about an axis passing through its median line 12 and preferably this pivotal axis or axis of rotation is within the leading third of the chord length of the overall vane 10. A transversely extending shaft 18 is carried by or attached to central section 12 in any convenient manner so that rotation of the shaft 18 will cause rotation of the central section 12. The ends of the shaft 18 are shown journalled in suitable supporting collars 19 which are rigidly secured to or may be integral with a stationary pivot support bracket 20. Therefore upon movement of the shaft 18 the nose section 12 will be rotated relative to the stationary supporting bracket 20 and the collar 19.

Any suitable means may be provided for imparting controlled rotation to the shaft 18 and central section 12 such as control linkages 21 and 21 which can be connected to the standard control system for the aircraft, ship, or the like.

To provide a continuous and uninterrupted curve in either the fully positive or fully negative positions, link and lever means connect the central section 12 with the nose section and the flap section for translating partial rotation of the central section into partial rotation of the flap section (in the same direction of rotation) and of the nose section (in a direction opposed to the direction of rotation of the central section). A pair of links 22 and 22' may be provided on either end of the vane for pivotally connecting the levers 15 and 15 with an offset pivot lug on each of the stationary collars 19.

In a like manner, a pair of links 23 and 23' are pivotally connected at stationary pivot points on the collar 19 and are pivotally connected to the levers 17 and 17 to actuate and rotate the flap 13 about its pivotal axis. The links 22 and 22 are generally of shorter length than the links 23 and 23'. Also, the links 22 and 22 are pivotally connected above the shaft 18 while the longer links 23 and 23 are pivotally connected below the shaft 18 to the collar 19. Although in the form shown, the levers 15 and 17 both extend above the median line of the vane and the links 22 and 23 are pivoted at points above and below the median lme in the vicinity of the pivot axis of shaft 18, the invention is not limited thereto, and other arrangements and means adapted to provide the desired partial rotation and produce the results and mode of operation herein disclosed may be used.

As can be seen in FIG. 3, with this type of lever and link structure, when the central section is partially rotated, the flap section 13 will be rotated in the same direction While the nose section 11 will be rotated in a direction opposed to the direction of rotation of the central section. In order to provide a substantially smooth curve in any position for the vane, the angular displacement of the nose and flap sections with respect to the central section is less than the angular rotation of the central section about its axis from its initial neutral position. It has been found that suitable results have been obtained by providing link and lever means which form an angle between the median line 11' of the nose section and the median line 12 of the central section that is equal to the angle between the median line 13 of the flap section and the median line 12 of the central section for any variation in the camber of the vane after movement from the neutral position. It should be also noted that the link and lever means are so connected to the sections to allow the angular displacement of the nose and flap sections with respect to the central section to be less than the angular rotation of the central section about its axis. These angular relationships, however, can vary considerably depending upon the particular vane articulation.

As the vane is actuated from its neutral position towards the fully negative or the fully positive camber position, it can be seen in FIG. 3 that the link and lever means 17 and 23 allow the upstream portion 13a of the flap to rotate upstream relative to the spanwise edge 12c and be spaced therefrom to provide a slot therebetween allowing fluid to pass from the high pressure side of the vane to the low pressure side of the vane. As the vanes camber is varied towards the fully negative or fully positive position, the slot between the flap and central sections becomes wider thus allowing more fluid to pass therebetween. By providing such a slot, the turbulence and burbling which tend to occur on the low pressure side of the vane is eliminated by the fluid stream passing through the slot. This burbling and turbulence of the fluid stream generally tends to build up when the vanes camber has been varied greatly to either the fully negative or fully positive position. As stated hereinabove, by eliminating this turbulence and burbling of the fluid stream, the separation is substantially reduced thus resulting in a greater normal control force.

As seen in FIG. 2, each of the sections 11, 12 and 13 is symmetrical about its respective median line whereby in neutral position of the articulated vane, the median lines of all the sections are in alignment to provide a symmetrical vane having substantially continuous outer contours of virtually no drag. While the axes of rotation for the various sections can be located at various points along the chord length of the vane, it has been found that a suitable controllably articulatable vane is provided when the shaft or trunnion 18 is located in the first /3 of the chord of the entire articulated vane (from the leading edge of the nose in neutral position) and preferably at a zone between 26% and 32% of the total chord, the nose is preferably narrower than the flap, the nose axis (14), is preferably located at between 15% and 24% of the total chord; the flap axis is preferably located at between and of the total chord. With an articulated vane coming within these proportions and a linkage arranged to translate rotation to all of the sections, a vane is provided which will produce a maximum control force with substantially no drag in all positions.

Referring to FIG. 4, a controllably articulatable vane 10a is shown which is substantially similar to the vane 10 in FIGS. 1 to 3. The central section 32 of the vane 10a is provided with a downstream portion 32b which is symmetrically tapered in a downstream direction about its median line 32 to terminate in a spanwise edge 32c similar to the spanwise edge 12c. The taper of the downstream portion 32b of the central section 32 begins at substantially the midpoint of the central section 32 rather than at the furthermost downstream area of the central section 32 asprovided by section 12. This provides a smooth gradual taper for the outer contours terminating in the edge 32c. In all other respects, the sections 11 and 13 and the link and lever means are the same as shown and described above for the articulatable vane 10.

While the articulatable vane illustrated as or 10a can be utilized in various mediums, FIG. 5 illustrates that a plurality of vanes 10 can be pivotally mounted in a thrust propulsion unit having an open ended duct 31 provided with centrally disposed axially mounted impellers 33. This type of open ended duct thrust propulsion can be utilized in a vertical take-01f aircraft having such a thrust propulsion unit rotatably mounted on either side of the longitudinal axis of the aircraft, such use being shown and described in copending application Serial No. 473,313 now Patent No. 2,788,435, May 26, 1959 entitled Aircraft Construction.

The vanes 10 which are pivotally mounted in the outlet portion of the thrust propulsion unit 31 may be interconnected by suitable linkage 34 so as to move simultaneously in the same direction. It should be noted that the articulatable vanes 10 could be also utilized in the inlet portion of the duct unit 31 so as to vary the direction of the air entering the duct 31. By so varying the direction of the air, the loading on the impellers could be thus controlled as provided in an application filed by Charles W. Morris et al., on an Aircraft Flight Control System.

It can thus be seen that an articulatable vane has been provided which is perfectly symmetrical in the neutral position to provide substantially continuous outer contours of virtually no drag and which can be varied to change its upper camber to either a fully positive or fully negative position. This allows the vane to deflect the air stream in either direction from the neutral position to provide suitable normal controlling forces for the device to be controlled. This type of articulatable vane can be used in Various ways on diiferent devices, such as aircraft rudders, anti-roll vanes for ships and vessels, inlet or outlet guide vanes of a ducted fan propulsion unit, submarine controls, vanes for various lighter-than-air devices, and various control surfaces on an aircraft such as rudders, elevators or wing-tip ailerons.

It has been found that the articulatable control vane of the present invention is capable of deflecting the fluid through a greater angle to produce a normal control force of greater magnitude than other vanes used heretofore.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that Within the scope of the appended claims invention may be practiced otherwise than as specifically described.

I claim:

1. A controllably articulatable vane adapted to be positioned in a fluid stream and adapted to be varied between positions wherein the upper camber is fully positive, neutral and fully negative, comprising: a central section, a nose section and a flap section, each section being sym metrical about its median line, said nose section having an unobstructed leading edge adapted to engage the fluid stream, said nose and flap sections being pivotally connected respectively to the upstream and downstream portions of the central section about axes passing through said central section, whereby in neutral position of said articulated vane the median lines of all of said sections are in alignment to provide a symmetrical vane having substantially continuous outer contours, means pivotally mounting said central section about an axis passing through said central section median line, means for imparting controlled rotation to said central section about its axis, and link and lever means connecting said central section with the nose section and with the flap section for translating partial rotation of the central section into partial rotation of the flap section in the same direction of rotation and of the nose section in a direction opposed to the direction of rotation of the central section.

2. A controllably articulatable vane as stated in claim 1 wherein said link and lever means is so connected to said sections to produce a smaller angular displacement of said nose and fiap sections with respect to the central section, than the angular rotation of said central section about its axis.

3. A controllably articulatable vane adapted to be positioned in a fluid stream and adapted to be varied between positions wherein the upper camber is fully positive, neutral and fully negative, comprising: a central section, a nose section and a flap section, each section being symmetrical about its median line, said nose and flap sections being pivotally connected respectively to the upstream and downstream portions of the central section about axes passing through said central section, whereby in neutral position of said articulated vane the median lines of all of said sections are in alignment to provide a symmetrical vane having substantially continuous outer contours of virtually no drag, the downstream portion of said central section being symmetrically tapered in a downstream direction about its median line and terminating in a spanwise edge immediately adjacent the upstream portion of said flap section in the neutral position, and said upstream portion of the flap section being rounded and having a substantial thickness.

4. A controllably articulatable vane as stated in claim 3 including means for imparting controlled rotation to said central section about its axis, and link and lever means connecting said central section with the nose section and with the flap section for translating partial rotation of the central section into partial rotation of the flap section in the same direction of rotation and of the nose section in a direction opposed to the direction of rotation of the central section.

5. A controllably articulatable vane as stated in claim. 4 wherein the axis of said central section is within the leading third of the vane chords length, whereby said vane may assume a position wherein the upper camber thereof is fully positive and a position wherein the camber thereof is fully positive and a position wherein the camber is fully negative with negligible variation in location of the center of pressure.

6. A controllably articulatable vane as stated in claim 4 wherein said link and lever means is so connected to the sections to allow the angular displacement of said nose and flap sections with respect to the central section to be less than the angular rotation of said central section about its axis, wherein the link and lever means impart a smaller angular rotation to the nose and flap sections with respect to the central section than the angular rotation of the central section about its axis.

7. A controllably articulatable vane as stated in claim 4 wherein said link and lever means is so connected to the sections to allow the angular displacement of said nose and flap sections with respect to the central section to be less than the angular rotation of said central section about its axis, wherein rotation of the central section about its axis is translated into a rotation of the flap with respect to the central section in the same direc tion but of smaller magnitude and the spanwise edge assumes a position spaced from the portion of the flap section to permit fluid to be directed from the high pressure side of said vane to the low pressure side of the vane.

8. A controllably articulatable vane adapted to be positioned in a fluid stream and adapted to be varied between positions wherein the upper camber is fully positive, neutral and fully negative, comprising: a central section, a nose section and a flap section, each section being symmetrical about its median line, said nose and flap sections being pivotally connected respectively to the upstream and downstream portions of the central sections about axes passing through said central section,

whereby in neutral position of said articulated vane the median lines of all of said sections are in alignment to provide a symmetrical vane having substantially continuous outer contours, the downstream portion of said central section being symmetrically tapered in a downstream direction about its median line and terminating in a spanwise edge immediately adjacent the upstream portion of said flap section in the neutral position, said upstream portion of the flap section being rounded and having a substantial thickness, and the downstream portion of said nose section being concaved to receive a convexed upstream portion of said central section whereby smooth, uninterrupted contours are provided between the sections in any position of the vane.

9. A controllably articulatable vane as stated in claim 8 wherein said nose axis is located at 20% of the length of the vane chord measured from the leading edge of the vane in its neutral position, said axis of the central section is located at 30% of the length of the vane chord measured from the leading edge of the vane in its neutral position, and said flap axis is located at 65% of the length of the vane chord measured from the leading edge of the vane in its neutral position.

10. A controllably articulatable vane as stated in claim 8 including means pivotally mounting said central section about an axis passing through said central section median line, means for imparting controlled rotation to said central section about its axis, and means connecting said central section with the nose section and with the flap section for translating partial rotation of the control of the central section into partial rotation of the flap section in the same direction of rotation and of the slat section in a direction opposed to the direction of rotation of the central section.

11. A controllably articulatable vane as stated in claim 10 wherein the axis of said central section is Within the leading third of the vane chords length, whereby said vane may assume a position wherein the upper camber thereof is fully positive and a position wherein the camber is fully negative with negligible variation in location of the center of pressure.

12. In combination with an open-ended thrust-producing unit having an inlet portion and an outlet portion, the provision of a plurality of articulatable vanes in the fluid stream passing through said unit, each of said vanes comprising a central section, a nose section and a flap section, each section being symmetrical about its median line, said nose section having an unobstructed leading edge adapted to engage the fluid stream, said nose and flap sections being pivotally connected respectively to the upstream and downstream portions of the central section about axes passing through said central section whereby in neutral position of said articulated vane the median lines of said sections are in alignment to provide a symmetrical vane having substantially, continuous outer contours and means pivotally mounting said central section on said thrust-producing unit about an axis transverse to the axis of said unit and passing through said central sections median line.

13. In a combination as stated in claim 12 the provision of: means for imparting controlled rotation to said central section about its axis, and link and lever means connecting said central section with the nose section and with the flap section for translating partial rotation of the central section into partial rotation of the flap section in the same direction of rotation and of the nose section in a direction opposed to the direction of rotation of the control section, the angular displacement of said nose and flap sections with respect to the central section being less than the angular rotation of said central section about its axis, so that upon rotation of the central section the upstream portion of the flap begins to rotate upstream relative to the downstream portion of the central section to provide a slot therebetween allowing fluid to pass from a high pressure side of the vane to the lower pressure side of the vane.

14. A controllably articulatable vane adapted to be positioned in a fluid stream and adapted to be varied between positions wherein the upper camber is fully positive, neutral and fully negative, comprising: a central section, a nose section and a flap section, each section being symmetrical about its median line, said nose and flap sections being pivotally connected respectively to the upstream and downstream portions of the central section about axes passing through said central section, whereby in neutral position of said articulated vane the median lines of all of said sections are in alignment to provide a symmetrical vane having substantially continuous outer contours, means pivotally mounting said central section about an axis passing through said central section median line, means for imparting controlled rotation to said central section about its axis, and link and lever means connecting said central section with the nose section and with the flap section for translating partial rotation of the central section into partial rotation of the fiap section in the same direction of rotation and of the nose section in a direction opposed to the direction of rotation of the central section, the axis of rotation of said central section being within the leading third of the vane chords length, whereby said vane may assume a position wherein the upper camber thereof is fully positive and a position wherein the upper camber is fully negative with negligible variation in location of the center of pressure.

References Cited in the file of this patent UNITED STATES PATENTS 2,416,958 Sears Mar. 4, 1947 2,813,689 Norton et al Nov. 19, 1957 FOREIGN PATENTS 985,498 France Mar. 14, 1951 

